John f



(No Model.)

J. P.4 CLEMENT.

IMPACT TOOL.

Patented June y7, 1887.l

\ did. 'l l,

UNITED STATES A PATENT OFFICE.

JOHN F. CLEMENT, OF PHILADELPHIA, PENNSYLVANIA.

iMPAoT-TooL.'

SPECIFICATION forming part of Letters Patent Iva-364,481, dated `lune 7, 1887.

Application filed February 14, 1857. Serial No. QQLSDQ. (No model.) l

, ing to insure the rapid operation of the tool,

and to provide a ready means of regulating the force of the blow.

In the accompanying drawings, Figure 1 is a longitudinal sectional View of an impact-tool constructed in accordance with myinvention. Fig. 2 is a sectional view of the pump for operating the same. Figs. 3 and 4 are views of parts of the tool, showing a controlling-valve adjusted to different positions from that shown in Fig. 1. Fig. 5is a transverse section of the lower portion of the device. Fig. 6 is a view illustrating la method of operating a pump for the tool shown in Fig. 1. Fig. 7 is a viewof a valve structure adapted for use in connection with the tool when the latter is operated by a single-action pump, aud Fig. S is a view of another singleaction tool with moditied form of regulator. I

In Fig. 1, A represents a cylinder contain ing a plunger or ram, B, which can movefreely in said cylinder. The lower end of the cylinder is closed by a tubular plug, a, in whichis guided and free to slide a stem, D, the upper end of which projects into the cylinder, and has a ange or collar, b, forming a bearing for a spring, d, which is contained partly in a recess in the inner end ot' the plug a, and tends to elevate the stem D to an extent permitted by the head of a stop-screw, f, the stem of the latter passing through an opening in the flange b, and having a thread adapted to aninternal thread Yin an opening in the inner end of the plug a, so that by a proper adjustment of the screw the extent of inward movement or lift of the stem D, due to the action of the spring d, can be readily regulated.

In the bottom of the spring-receiving recess of the plug a is a washer, i, of rubber or like material, fitting snugly to the stem D, so as to prevent leakage around the same.

The tool F is secured tothe stem D by means of a transverse key, g, adapted to recesses iu the tool and stem, the opposite projecting ends of this key being adapted to vertical' slots hin the plug a, so that longitudinal movement of the stem, and of the tool carried thereby, is always permitted, and ready access can be had to the retaining-key at any time, rapid changing of the tools being thus rendered possible.

XVith the lower end of the cylinder A communicates a pipe, m, a similar pipe, n, communicating with the upperend of the cylinder, and these pipes communicate, through ilexible tubes p, with pipes n mf, respectively at the upper and lower ends of a pnmpcylinder, J, which contains a piston, J', the rod la of which is reciprocated in any suitable manner.

On the upward stroke of the piston air is forced' from the upper portion of the pump- Vcylinder into the upper portion of the cylinder A, and drawn from the lower end of the latter into the lower portion of the pump-cylinder, thus causing the downward movement of the plunger or ram B, which strikes a blow upon the inner end of the stem D and drives the latter forcibly downward. Ou the downward stroke: of the pump-piston the action is rcversed, air being forcedinto the lower end of the cylinder A and drawn from the upper end of the same, so as to cause the elevation of the ram B, the stem D being lifted by its spring d to the extent permitted by the stop-screwf. In order to prevent the ram in its upward movement from coming into forcible contactwith thc head a at the upper end of the cylinder A, a light spring, s, is interposed between said head and the ram, as shown. movement of the ram Bis thus du'e both to the direct impulse of the blast of air on one side andthe withdrawal of the air from the opposite side, so that a forcible blow is delivered by the ram.' In order, however, that the force of the blow may be regulated during the operation of the tool, as may bc required by the character of the work which is being per formed, I connect the pipes m and a by means of a transverse valve-chest, K, in which is a sliding valve, M, having two ports, t and t', the former passing directly through the valve, but the port t' being right-angled and extend` ing to the cud ofy the valve. When, therefore, the valve M is adjusted to the position shown in Fig. l, the How of air to or from the upper The e IOO end of the cylinder A is cut off and a direct communication is established between the two pipes m and n, so that air iiows directly from one to the other, and no influence is exerted upon the ram B.

When the valve is adjusted to the position shown in Fig. 8, there is a restricted communication between the pipes m and n, and a restricted communication between the pipe n and the upper end of the cylinder A, so that the ram is subjected to but a portion of the full force of the blast, while, when the valve is adjusted to the position shown in Fig. 4, direct communication between the pipes m and a is cut off and free communication opened between the pipe a and the upper end of the cylinder A, so that the ram acts with full force.

The valve M has a projecting stem, which is depressed in order to operate the valve, a spring, t, serving to move the valve outward.

The valve-stem may be under the iniiuence of an arm, w, at the side of the cylinder, as shown, for instance, by dotted lines in Fig. l, so as to provide for the ready operation ofthe valve from any point in the length of the cylinder.

The form of valve described may be used with advantage in connection with a tool operated by a single-acting pump, in which case but a single air-pipe is used, one end of the valve-chest being open to the atmosphere, as shown in Fig. 7.

Other means within the scope of my invention may be used for regulating the force of the blow inasingle-acting tool. Forinstanee, in Fig. 8 I have shown a construction in which a simple branch tube, c, communicates with the blast-pipe at a point between the pump and the ram-cylinder, this tube having a series of oriiices, c', which may be covered by the lingers of the hand in which the tool is held, the area of opening for the inlet of air to or its discharge from the branch pipe being regulated by moving the fingers so as to uncover one or more 0f the oritiees; or the pipe may, if desired, be open at the end, and maybe elastic, so that it can be compressed to a greater or less extent by the finger, as may be suggested by the desired regulation of area of the passage provided by the pipe.

The pump shown in this apparatus is a cylinder with a diaphragm, V, instead of a piston, this form being preferred for use in connection with a single-acting tool.

Prior to my invention pneumatic pluggers have been devised in which the force of the blow delivered by the ram is regulated by restricting the inlet of air to or its discharge from the cylinder below the ram, or by restricting the flow through the blast-pipe; butV both of these plans are objectionable, on account ofthe back-pressure or drag upon the pump, which results from such restriction. My invention differs from these in effecting the regulation, by providing the blast-pipe with means :for supplying said pipe with air, or for the escape of air from said pipe at a sis-1,481

point between the pump andthe ram cylinder.

This independent supply and discharge is in the nature of a leak in the blast-pipe, and hence weakens the force of the blast or partial vacuum to the extent of the volume of said leak.

Although in the case of the double-action tool there is a partial obstruction of the communication between the blast-pipe and the cylinder, this is always counteracted by the pl'ovision of an independent means of supply and discharge equal to the obstruction in the regular communication, so that there is never any back-pressure or drag to interfere with the perfect freedom and uniformity of movement of the pump, or with the free reciproca; tion of the rain in its cylinder.

I can use the ordinary form of dental engine for operating either the double-acting pump shown in Fig. l or the single-acting pump shown in Fig. S when my improved impacttoolis to be used as a dental plugger. In this case I bolt the standard carrying the pump directly to the vertical post or column l? of the dental engine, the driving-shaft u of the pump having a pulley for receiving, as shown by dotted lines in Fig. 8, the belt x from the drive-wheel S,which isoperated by the treadle. Said shaft a is also provided with a crankdisk, 1, a rod from which is connected either to the diaphragm V of the single-acting pump or to the piston-rod 7c of the pump when the latter is double-acting.

In order that I may use for the purpose of driving the pump the same belt x which is used for driving the ordinary tool-operating shaft, T, of the dental engine, I provide said belt with a detachable section, a7', the removal of which shortens the belt to the extent necessary to adaptit for driving the pump-operating shaft a, which'is somewhat below the shaft T, ordinary hook-and-eye couplings being used to connect the ends of the belt x to the ends of the section m', or for connecting the ends of said belt x together when the section x is removed.

I am aware that a pneumatic plugger has been devised in which the pump was operated by direct connection with the drive-wheel S of a dental engine; but with such a device but a few blows per minute can bc given to the tool, whereas when the parts are constructed in accordance with my invention hundreds or thousands of blows per minute can be given.

I claim as my invention-'- 1. The combination, in an impact-tool, of the ram-cylinder and its ram, a pump, and a pipe connecting said pump to the ram-cylinder, said pipe having between the pump and the ramcylinder a passage through which air can enter or leave the pipe, all substantially as speci fied.

2. The combination, in an impact-tool, ofthe ram-cylinder and its ram, a pump, a pipe connecting the pump and cylinder, and having between the two a passage through which air can enter or leave the pipe, and means for regulat- IOO reg

ing the effective inlet or discharge area of said passage, all substantially as specified.

3. The combination, in an impact-tool, of the ranrcylinder and ram, a double-acting pump7 and pipes whereby communication is afforded between the opposite ends of the pump and corresponding ends of the ram-cylinder, all substantially as specified.

4. The combination of the cylinder and iis ram, the movable stem and its lifting-spring, and a stop-screw independent of said spring and adjustable in a direction parallel with the line of movement of the stem, so as to limit the lift of said stem by the spring, all substantially as specified.

5. rlhe combination of the ram-cylinder and ram, a pump, a pipe connecting the pump and ram-cylinder, and a valve having two ports, one providing a direct communication between the pipe and cylinder and the other serving to divert the current, all snbstanti ally as specified.

6. The combination of the ram-cylinder and its ram, the pump, the two pipes, one communicating with one end of the cylinder and pump and the other with the opposite ends thereof, avalve=chest connecting the two pipes, and a valve having two ports, one forming a dia rect communication between one of the pipes and the cylinder and the other providing a direct communication between the two pipes, all substantially as specified.

7. The combination of a dental engine, the ram-cylinder and its ram, the pump, and a connecting-pipe, a pump-carrier mounted on the post ofthe dental engine, a pump-operating counter-shaft, and a belt whereby said shaft is operated from the drive-wheel ofthe engine, all substantiallyas specified.

8. The combination of a dental engine, its drive-wheel and tool-operating shaft, a pump structure mounted on the standard of the engine, and a driving-belt having a detachable section, whereby it can be used either for driving the tool-operatin g sh aft of the engine or the operating-shaft of the pump, all substantially as specified.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN F. CLEMENT.

Vitnesses:

WILLIAM D. (DONNER, HARRY SMITH. 

